Fecal impaction causing mega-rectum – a cause of colorectal catastrophes.
Case reports of Fecal impaction
A 92 year old female presented complaining of loose bowel motions, vomiting, and abdominal pain. She gave a history of ischemic heart disease, congestive heart failure, anemia, and non-insulin dependent diabetes mellitus. She had had a coronary artery bypass graft, a right carotid endarterectomy, and a permanent pacemaker insertion performed in the past. Physical examination revealed a lethargic elderly lady with poor peripheral perfusion, blood pressure- 70/40, paced heart rate – 68/min, respiratory rate – 36/min, and temperature – 98 degrees F. Her abdomen was very distended, diffusely tender with guarding. Rectal examination revealed a large amount of soft feces- guaiac-negative. While cell count was 36.9 thousands, BUN and creatinine levels were 30mg% and 2mg%, respectively. Arterial blood gases showed metabolic acidosis with PH of 7.1 and base excess of minus-14. Plain abdominal X ray revealed distended large bowel with a large amount of feces in the rectum. The patient underwent endotracheal intubation and fluid resuscitation was initiated. Pre-operative intra-abdominal pressure (IAP)-measured through the urinary bladder- was 25 cm’ water. APACHE II score was 25. At operation, a mega-rectum, 15 cm’ in diameter, impacted with massive amount of feces- was found. It appeared paper-thin and gray-dusky, suggesting non-viability. The rectum had to be manually dis-impacted so that a low Hartmann’s procedure, using a TA-90 liner stapler, could be performed.. From the outside the sigmoid colon used to fashion the end colostomy appeared viable but it’s mucosa was dusky-looking and of uncertain viability. Due to the critical state of the patient a decision was made to conclude the operation and a second look laparotomy was planned. Because of the intra-abdominal hypertension the fascia was left open, bridged with an absorbable synthetic mesh. Postoperatively the patients respiratory and cardiovascular systems improved dramatically but the colostomy appeared necrotic. 48 hours later, the patient was re-operated; the ischemic sigmoid and left colon resected and a end transverse colostomy fashioned; the abdomen was closed. Postoperative course was uneventful. Pathological report of the rectum and colon documented transmural necrosis.
A 88 year old lady was admitted with a week history of an increased abdominal distention and pain accompanied by vomiting. Her previous medical and surgical history were unknown. On examination the patient was alert and hemodynamically stable. The abdomen was distended and moderately tender. Abdominal X-ray revealed massive fecal impaction producing a mega-rectum; chest radiograph showed free subdiaphragmatic air. Preoperative APACHE II score was 14. After resuscitation a laparotomy was performed disclosing a cecal perforation secondary to obstruction of the colon-which appeared non-viable-caused by the fecal impaction. A subtotal colectomy with ileostomy were performed; the viable distal rectum was cross -stapled after it’s manual dis-impaction. Recovery was uneventful.
Severe constipation resulting in fecal impaction of the rectum is “bread and butter” for physicians managing our aging population. When neglected, fecal impaction may lead to severe complications such as respiratory arrest, obstructive uropathy, acute lower limb ischemia and hepatic encephalopathy. Surprisingly, surgical gastrointestinal complications of fecal impaction remain underreported.
Fecal impaction in the rectum may cause colonic obstruction requiring an operative treatment. Massive fecal impaction of the rectosigmoid may result in perforation of the recto-sigmoid as reported previously. Often the diagnosis is made only at autopsy as emphasized by Wang and Sutherland.
The above cases from the literature as well our two case- reports represent fecal impaction with soft clay-like stool. Colorectal stercoral ulceration and perforation by hard, impacted feces has been, however, better recognized as a relatively common and neglected medical and surgical problem, causing “silent” death in the elderly population.
Our first case portrays that the mass effect created by the extreme dilatation of the rectum may produce severe intra-abdominal hypertension, causing cardiovascular and respiratory collapse and renal dysfunction- representing a typical abdominal compartment syndrome. The latter, further decreases splanchnic perfusion, aggravating colorectal ischemia. Rectal dis-impaction and abdominal decompression rapidly reversed the adverse physiological manifestations of the intra-abdominal hypertension. This case is also suggests that lessons learned in trauma surgery, where “damage control-abbreviated laparotomy” policies are life saving in the critically injured, unstable patients, may be successfully put to use in non-traumatic abdominal catastrophes.